BQCA is primarily used in scientific research as a selective positive allosteric modulator of the M1 muscarinic acetylcholine receptor. Its main application lies in studies related to cognitive function and neurological disorders, particularly Alzheimer’s disease. By enhancing the activity of the M1 receptor without directly activating it, BQCA helps improve signaling in brain pathways involved in memory and learning. This makes it a valuable tool for investigating potential treatments for cognitive impairment. It has also been used in preclinical studies to understand receptor mechanisms and to develop novel therapeutics targeting muscarinic receptors with greater specificity and fewer side effects.